J.LO’S TURN: Even the jaded fashion crowd was impressed when Jennifer Lopez showed up at the Marchesa presentation on Wednesday. The very pregnant star (who’s due in the next few weeks) got a tour of the collection at the Chelsea Art Museum from the Marchesa designers, Keren Craig and Georgina Chapman. “I like the very big ones,” joked Lopez, wearing a blue knee-length Notte by Marchesa frock as she took it all in.

Meanwhile, her husband, Marc Anthony, told Craig about domestic life. “I can’t complain about anything in the house anymore. But I’ll be there to support. I don’t know about the squeezing stuff, but I’ll be there.”

This season is no exception, as Jacobs has invited Kevin Federline to attend. But Federline, who’s in town for meetings about a possible acting gig and who also will attend the Sean John show, will have to trade in his signature wifebeaters and white kicks. Jacobs is dressing Federline from his men’s line for the occasion. And any concerned Britney Spears watchers need not fear: Federline is only in town for the day, so he won’t be separated from their two sons for long.

Meanwhile, Jacobs has tapped M.I.A. for his post-show bash at 24 Fifth Avenue. The Sri Lankan rapper won’t be performing her own tunes, though: She’s slated to be DJing for the night.

TOMMY PRESHOW: Tommy Hilfiger is bringing culture back — bringing fashion week to Lincoln Center tonight by transforming Avery Fisher Hall’s Grand Promenade into a runway. According to the American design house, this is the first time a designer has taken center stage at Lincoln Center since Geoffrey Beene in the Nineties — or Bill Blass in the Sixties, for the next most recent. After sitting together at Sari Gueron over the weekend, Maggie Gyllenhaal and Julianne Moore are both again expected at today’s show. Moore visited the new Tommy Hilfiger women’s boutique on Bleecker Street to chose an outfit for the occasion, while Ioan Gruffudd, from the “Fantastic Four” movies, shopped at the Tommy Hilfiger SoHo store Thursday to find something fitting.

A RASTED DEVELOPMENT: The sexy was back downtown Tuesday night as Justin Timberlake and Trace Ayala hosted a cocktail party at the New York home of their new William Rast design collaborators, Paris 68’s Johan and Marcella Lindeberg. Found mingling among the crowd of editors and buyers — not to mention Simon Le Bon and Jeff Gordon — were a dozen models sporting the expanded and much more tailored collection. “It’s everything I like,” said Timberlake, “a little utilitarian, a little bit street.”

A little bit pricy, as well. According to vice president of merchandising Brad Virata, while the jeans will continue to wholesale between $90 and $100, the collection is priced at upward of $75 for a T-shirt to $600 for a leather jacket. “The goal was to be below Theory but above Diesel,” he said.

“The prices are up,” agreed Ayala, “but the line is more directional and, really, it’s where Justin and I wanted it to go from the beginning.” That apparently means the requisite denim range plus a heady dose of jackets with details like exaggerated collars and custom patches, lush knits for layering and flirty pull-on or double-breast miniskirts in pinstripe wool or cotton canvas. Up next: shooting the label’s first ad campaign this spring.

DOUBLE TROUBLE: For those who missed CocoRosie at Prada’s Tuesday night bash or The Slits at Chloë Sevigny and Opening Ceremony’s Webster Hall blowout, tonight brings another party-cum-live performance with Anna Sui’s official after-show party at Don Hill’s. The Paddingtons will be bringing down the house for the first time on American turf at the fete, which also serves as Agyness Deyn’s birthday party. The Misshapes and Deyn herself also will take turns in the DJ booth up until 4 a.m., leaving revelers just enough time to catch a few hours of shut-eye before the Ralph Lauren show the next morning.

BACK TO BACK: Phillip Lim took his front-row seat at Richard Chai’s show on Wednesday — even as his own fall presentation was scheduled for the slot right after. “I did extra prep time before,” Lim said, adding jokingly: “He would kill me if I wasn’t here, and I don’t want to die an early death.”

Post-show, Lim even had enough time to pop backstage for a quick hello and a hug for his best friend. And Chai was spotted at Lim’s show right after his own. As Dionne Warwick would say, that’s what friends are for.

THEY’RE ALL FRIENDS: Fifteen minutes after his scheduled 11 a.m. showtime, Michael Kors was the picture of calm, charming and posing with the gaggle of VIPs (Raquel Welch, Natasha Richardson, Ellen Pompeo) in the backstage suite. “I am not going to the show,” the designer joked. “I am watching it here on the screen, and Tivo-ing it on ‘Full Frontal Fashion.'”

Debra Messing lamented she and her favorite fashion pal don’t get to see each other much outside of the fashion show circus. “It’s a long-distance love affair,” she said.

Eventually everyone made it to their seats in the front of the house, where Wendi Murdoch took in her first and only fashion week show with her friend, Celia Chou, whose husband, Silas, owns a stake in Kors’ business. Asked what she thought of the Wall Street Journal, which her husband, Rupert, recently snapped up, Murdoch said: “It’s great. My husband loves it, and I think they will have a lot more fashion.” She herself reads it every morning, particularly the stories her husband marks for her. “He does the press clippings,” she joked.

Donald and Melania Trump also caught the show, but unfortunately had to leave little Baron at home. Does the little heir share the Mrs.’ fashion gene? “Oh yes,” Trump said. “Every time I’m getting dressed, he sits there and goes, ‘Wowww!'”

Eva Longoria Parker also popped in at the last second and took her seat next to Pharrell Williams. But it wasn’t the only chance for “Desperate Housewives” fans to catch her: Today she’s expected at Naeem Kahn and Zac Posen.

HALSTON HIT: Fashion critics may be divided over Marco Zanini’s first collection, but some consumers have given it their vote of confidence. Twenty-four hours after a limited run of two key dresses from the runway went on sale at Net-a-porter.com on Tuesday, the designer e-commerce site reported the venture to be a hit. Some 25,000 women had logged on to see an edited version of the runway show within 60 minutes of it being posted. Net-a-porter.com’s stock of Halston’s $1,495 wool jersey shirtdresses sold out within 45 minutes of going on sale and, by noon on Wednesday, 85 percent of the $1,795 jersey drape cocktail dresses had been sold. But Net-a-porter.com did not disclose the number of units it had bought of each style.

“This is a groundbreaking project for us and the speed at which we have seen orders coming in from around the world is extraordinary,” said Natalie Massenet, Net-a-porter.com’s chairman and founder.

PARTY FOUL: Chloë Sevigny was not the happiest of campers Tuesday night at the Bryant Park Hotel’s Cellar Bar, where she hosted the launch of Samsonite’s Black Label Trunk Collection. The scenester was out until the wee hours the night before at the bash she hosted at Webster Hall. “I’m just really tired,” said Sevigny, clad in vintage yellow Ungaro. “I was out really late, then up shooting Uniqlo ads all day.” Other than the raucous rage schedule, what else about fashion week gets the downtown diva’s Wolfords in a bunch? “Fashion week makes me feel very self-critical,” she explained. “Like I’m not wearing the right thing or looking the right way. It’s stressful.”

LIZ CLAIBORNE INVADES ISAAC MIZRAHI: In addition to front-row hopping at Isaac Mizrahi, who just signed on to design the Liz Claiborne line, and Narciso Rodriguez, in which Liz Claiborne Inc. owns a 50 percent stake, Claiborne chief executive officer William L. McComb said he’s had “a good fashion week with good conversations and meetings with people who have been in town.”

McComb wouldn’t elaborate on the nature of the meetings, nor would he confirm this morning’s meeting to close on the sale of Ellen Tracy to a consortium of buyers led by Windsong Brands and the Radius Group. The ceo did say, though, that Claiborne is closing in on a new co-president for Kate Spade to handle the business side, complementing co-president Deborah Lloyd, who was hired for the design side in October. Also at the show was Dave McTague, Claiborne executive vice president of partnered brands — raising the question of whether the firm’s ties to Mizrahi go deeper than his designing its flagship line. Perhaps Claiborne is considering a similar investment setup to the one it has with Rodriguez? “While we obviously would like to grow our relationship, our current collaboration is 100 percent focused on the Liz Claiborne brand,” a spokeswoman for Claiborne said.

Although Tim Gunn was missing from the Claiborne executive lineup at the show, his “Tim Gunn’s Guide to Style” sidekick Veronica Webb sat front row in an Mizrahi pink-and-white-checkered dress she’d also worn on the Bravo reality show. But she’s not joining Gunn on the show’s second season, instead opting to host her own show, “Living Style,” on BBC World, for which she covered Halston earlier in the week.

STAR TURN: Yes, even celebrities get starstruck. While sitting front row at the Matthew Williamson show on Tuesday afternoon, Rihanna discussed her plans to perform at the Gucci dinner on Wednesday night, which Madonna hosted. “I’ve never met her before,” the singer said of Mrs. Ritchie, before adding: “I hope I don’t cry.” Seated next to the chanteuse was Joy Bryant — who had changed outfits since attending Monique Lhuillier that morning. “Well, that was at 11 and now it’s five,” the actress said of her midday wardrobe switch, by way of explanation. And, indeed, Bryant had impending plans to don her third ensemble of the day: at Raoul’s, where Cosmopolitan magazine was feting its March cover girl — Rihanna.

LA VIE EN ROSE: Despite the cancellation of Vanity Fair’s post-Oscars bash, Tuesday night’s Chopard-hosted party for best-actress Oscar nominee Marion Cotillard at Chateau Marmont’s Bungalow One reflected the now-upbeat mood in Hollywood due to the reportedly imminent end of the writers’ strike. The timing was right; the Motion Picture Academy’s official nominees luncheon took place earlier that day at the Beverly Hilton, where actors and directors got to bask in the “everyone’s still a winner” glow. Later, Cotillard was joined by fellow nominee Amy Ryan, Ellen Von Unwerth, Erin Fetherston and directors Lawrence Kasdan and Amy Heckerling. As the belle de nuit at the Bungalow, which was decked out in red roses and pink pastries, a Chloé-clad Cotillard sighed, “I’m just having fun. There’s beauty in everyone you meet.”